Blar i Published externally på forfatter "Axelsen, Bjørn Erik"
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Acoustic observations of dusky dolphins Lagenorhynchus obscurus hunting Cape horse mackerel Trachurus capensis off Namibia
Bernasconi, Matteo; Nøttestad, Leif; Axelsen, Bjørn Erik; Krakstad, Jens-Otto (Journal article; Peer reviewed, 2011-05-16)Predator–prey interactions of mammals and their fish prey in marine ecosystems are rarely identified and recorded. We document for the first time the underwater behaviour of hunting dusky dolphins Lagenorhynchus obscurus ... -
Acoustic observations of jellyfish in the Namibian Benguela
Brierley, Andrew S.; Axelsen, Bjørn Erik; Buecher, Emmanuelle; Sparks, Conrad A. J.; Boyer, Helen; Gibbons, Mark J. (Journal article; Peer reviewed, 2001-01-26)Multi-frequency acoustic data (18, 38 and 120 kHz) were collected in conjunction with pelagic trawl sampling for gelatinous macrozooplankton during a cruise to the Namibian Benguela in September 1999. Sampling focused ... -
An evaluation of the bottom trawl surveys in the Benguela Current Large Marine Ecosystem
Axelsen, Bjørn Erik; Johnsen, Espen (Journal article; Peer reviewed, 2014-07-02)Demersal fish, shrimp and cephalopod assemblages on the continental shelves and slopes off Angola, Namibia and the southern and western coasts of South Africa have been monitored in terms of fisheries-independent trawl ... -
‘Await’ in the pelagic: dynamic trade-off between reproduction and survival within a herring school splitting vertically during spawning
Axelsen, Bjørn Erik; Nøttestad, Leif; Fernö, Anders; Johannessen, Arne; Misund, Ole Arve (Journal article; Peer reviewed, 2000-10-19)Spatio-temporal aspects of spawning behaviour were investigated in a single school of Norwegian spring-spawning herring Clupea harengus, and are explained by changes in the relative importance of reproduction, predation ... -
Migration patterns in Norwegian spring-spawning herring: why young fish swim away from the wintering area in late summer
Kvamme, Cecilie; Nøttestad, Leif; Fernö, Anders; Misund, Ole Arve; Dommasnes, Are; Axelsen, Bjørn Erik; Dalpadado, Padmini; Melle, Webjørn (Journal article; Peer reviewed, 2003-03-04)Norwegian spring-spawning herring Clupea harengus make extensive feeding migrations in the Norwegian Sea during summer. At the end of the feeding season herring may meet conflicting demands between moving to areas with ... -
Towards the acoustic estimation of jellyfish abundance
Brierley, Andrew S.; Boyer, D.; Axelsen, Bjørn Erik; Lynam, Christopher P.; Sparks, Conrad A. J.; Boyer, Helen; Gibbons, Mark J. (Journal article; Peer reviewed, 2005-06-23)Acoustic target strengths (TSs) of the 2 most common large medusae, Chrysaora hysoscella and Aequorea aequorea, in the northern Benguela (off Namibia) have previously been estimated (at 18, 38 and 120 kHz) from acoustic ...